Grease Kettles

Grease Kettles

Grease kettles are pressurized tanks that are used to manufacture grease, a type of lubricant. They steam heat, mix and then cool the ingredients used to make lubricating grease, a substance widely used in industrial manufacturing processes. Grease refers to a semi-solid lubricant (not the fat from animals in food) that has a higher viscosity than oil. It is usually made from calcium, sodium or lithium soap and mixed with mineral or vegetable oil. Lubricating greases are used as sealants, to keep dust and air away and increase friction in machinery where two moving components come in contact with each other, such as bearings or gears. They are also used as lubricants where oil does not or cannot perform well, like operations which must be sterile for the medical, pharmaceutical, food and beverage industries. Industrial greases are very fire resistant, and can be made from either synthetic or natural ingredients. The automotive manufacturing, aircraft, railroad and industrial manufacturing industries all use grease made inside grease kettles. Grease kettles come in many different sizes, and can hold anywhere from 50 to 400,000 pounds of grease at a time. Most smaller kettles are made for short cycles and are used in testing laboratories.

Grease kettles are either pressurized or non-pressurized. Autoclave-style kettles, which use pressure, are able to accomplish every step in the grease manufacturing process within the kettle. Saponification, finishing and cooling are all done in a continuous process inside one grease kettle. Atmospheric grease kettles are not pressurized, and therefore cannot manufacture grease in one process. Instead, the soap is transferred to the kettle, where it then goes through grease finishing and cooling. They are usually made of carbon steel, are cylindrical in shape and have flat bottoms and tops. Stainless steel is sometimes used for a lower cost. Grease kettles are heated by steam, electricity or thermal fluid, and usually cooled by cold water. To ensure safe processing, grease kettles are double walled and have sturdy leg supports to prevent tipping on uneven flooring. Since many grease kettles are positioned atop mezzanines that have grid-like flooring, some grease kettles are equipped with shell-mounted brackets that attach to the metal bars. The substances that make grease are a dispersion of a thickening agent in a liquid lubricant (the mineral or vegetable oil). Since these two substances don't easily mix, high powered agitators in combination with a set of alternating propellers ensure that the mixture becomes completely homogenous.